050 HPM 1115

HPM November 2015

Got a story? Ring us on 01732 748041 or e-mail twood@unity-media.com SPECIALREPORT How do you ventilate high rise buildings? Advances in drainage and ventilation pipework valves means that secondary pipework systems, which are primarily used in high rise buildings, can now be replaced with other, more effective, systems. Ian Crickmore, technical director at Polypipe Terrain, explains how outmoded secondary stack systems are no longer the only option... Installers are always searching for ways to reduce installation time and simplify processes. With advances continually being made in the plumbing and installation industry, it can sometimes be difficult keeping up-to-date on the most contemporary methods. When installing drainage and ventilation pipework in high rise buildings, traditional design standards dictate that a secondary ventilation stack and branch pipework has to be incorporated into drainage design to overcome transient air pressure changes. This is to account for the positive and negative air fluctuations that can compromise water trap seals due to the unsteady flow of water through the pipe work. To maintain a state of equilibrium in a drainage pipework system, it is necessary to mitigate this change in air pressure immediately. This response time is critical for protecting water trap seals, with a traditional secondary pipework system thought to be the only way to provide this function. There are many factors to consider when installing secondary pipework systems, which continue to be the industry norm. Secondary ventilation stack and pipework requires a whole additional system to be installed which itself has many disadvantages. A SECONDARY STACK VENTILATION SYSTEM It stands to reason that installing a secondary stack ventilation system requires more installation time and materials and consequently takes up precious floor space, a major factor when limited space is taken into consideration. This method also proves to be a much less effective solution for very tall, or complicated, drainage systems as the time lag that occurs when communicating an increase or decrease in the ambient airflow in the pipework can result in a non performing drainage systems. Removing the need for a secondary pipework system means that first fix installation time is significantly reduced due to a decrease in the amount of materials, man power and time required to complete the installation. There are potentially significant savings to be made through the removal of secondary full drainage systems. Firstly, as less vents are required there is also a limited requirement for floor penetration to install fire collars, something a secondary vent system would always require. Taking this approach also means reduced time, material and resultant manpower costs. WWW.HPMMAG.COM P.A.P.A valves are a proven alternative to replacing traditional secondary vented drainage systems 50 NOVEMBER 2015 HEATING & PLUMBING MONTHLY The lack of a secondary vent also reduces the drainage pipework system footprint. This, in turn, allows for greater flexibility in the layout and design of internal drainage systems for engineers, architects and design professionals . This increased flexibility means that building designs, as well as room layout, are no longer dictated by strict pipework systems, providing numerous benefits to not only architects, but interior designers and building owners who ultimately have more sellable space. COMMERCIAL AND RESIDENTIAL HIGH RISE BUILDINGS Rather than a secondary ventilation piping system, air regulatory valves instead can be installed in both commercial and residential high rise buildings drainage stacks to balance negative air pressure fluctuations. An attenuator valve can also balance positive pressures, allowing multi-storey building designers to simplify their design of sanitary waste systems. Products such as the Polypipe Terrain Positive Air Pressure Attenuator or P.A.P.A. and Pleura valves are a proven alternative to replacing traditional secondary vented drainage systems. The P.A.P.A. is designed to react to and attenuate positive pressure transience within the drainage stack of high rise developments providing a perfect venting solution for any multi-storey building over ten storeys high. The Pleura valves are designed to allow air into the system when negative pressures are experienced. When these two valves are combined, the effects of positive pressure such as blown sink and WC traps and negative pressure siphoning traps are mitigated, thus removing the need for a traditional secondary vented pipework system. Ultimately, we work in an industry where time and cost of installation are of paramount importance. Educating contractors on the most up-to-date products is the most efficient way to save time and money. The P.A.P.A. and Pleura valves have been tested in buildings up to 39 storeys high and have British Board of Agrément and local authority building control approval, making them the best option for designers, architects and installers. enquiry number 122 Pleura valves (above and below) are designed to allow air into the system when negative pressures are experienced


HPM November 2015
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